The pancreatic islet isolation and vector core (Core B) is an integral component of this program project. The purpose of this core is to assist the project leaders and their investigative personnel in three critical ways: 1) isolation of large numbers of highly purified pancreatic islets, 2) quality control of purity, quantity, and viability of islets needed for physiological and molecular studies as well as for successful transplantation in diabetic recipients and 3) construction and quality controlled delivery of adenoviral vectors containing the desired recombinant gene. The overlapping and synergistic need for both isolated islet and recombinant adenoviral vectors by the investigators of this program project prompted us to propose the implementation of Core B. The need for such a core is particularly poignant given the lack of a bona fide and easily accessible islet isolation core at the University of Pennsylvania. Additionally, given our 'in-house' expertise in construction of adenoviral vectors, we fell that the most time- and cost-efficient means of developing adenoviral vectors is the proposed 'in house' Core facility\ (Core B).